Improved alloy for sabots of projectiles



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Letters Patent No. 93,137, dated Jaly 27, 1869; cntedcted July 15, 1869.

IMPROYED ALLOY FOR SABO'I'S OE PROJECTILES.

The Schedule referred to in those Letters Patent and making part of the lame.

To all whom it may concern:

Be it known that I, THOMAS Tar on, of Washington, in the District of Columbia, have invented a new and improvedMetallic Composition for the Sabots of Rifle or Smooth-Bore Projectiles; and I do hereby declare that the following is a full and exact description thereof.

The nature of my invention consists in a certain composition of metals forming an alloy for the sabots of rifle and. smooth-bore projectiles, so that, in connection with certain formations of the same, they will perform the best function or results, expand, take the grooves in the case ofriflecannon, or fly off after leaving the gun.

An experimental experience has enabled me to ascertain the best combinations of metals forming an alloy for the sabots of rifle-projectiles or of smooth-bore. Further extensive experiments have shown that an alloy, composed of tin, lead, and copper, forms a valuable composition for sabot-metal.

This composition has been used of late by the United States Army Ordiiance Bureau, inall their late experiments, with the view of testing its value. I have used it in my experiments on the IJO-pmmder, 300- pounder, and GOO-pouuder, moire-inch.

The sabot takes the grooves well, and they never strip inaction.

The use of tin in the alloy is to add strength to the compound, as well as to increase the lubricating quality, so necessary. Too great increase of tin causes the mass to crystallize, and form tubes on cooling, which weakens much the sabot; but by the addition of copper, within certain limits, further toughnessis given to' the compound, and without the formation of crystalline tubes.

I have found in practice that thc alloy may be va ried somewhat in its proportions, but the following is the composition of the alloy, and proportions I use generally for projectiles of heavy calibre: Tin, seventy-eight pounds; lead, one hundred and twenty pounds; copper, three pounds; that is to say, when the projectiles do not exceed in weight six hundred pounds, and with charges of mammoth powder not exceeding seventy-five pounds. I sometimes use six pounds of copper, but, in that case I dimiu ish the proportion of tin. The points to be desired are toughness and lubricating quality, with economy.

The use of lead gives, with tin and copper, softness, with great strength, with cheapness. T00 great increase of copper causes the alloy to retainits heat too long for practical purposes. \Verc a much larger proportion used than that given in the proportions set forth, a workman would require a great many more moulds, as the alloy runs so slowly, and it has not beenfound that any practical benefit would be den'ved from the addition of copper, over and above that given here in. But were heavier projectilesto be made than those now in use, and used with higher -chargs,forcharges with more explosive force, I would increase the proportion of copper materially, but I would also dimin-- ish the proportion of tin, as copper is less apt to form crystalline tubes than tin. v

In my extensive experiments, at Washington Arsenal and Fortress Monroe, I have used many alloys with lead and of lead, that is, lead forming the principal metal. I have found that antimony, zinc, and iron will harden lead, but they do not add to the strength 4 of the alloy or compound formed. Their tendency is to form alloy of hardness, with brittleness, and wholly void of the lubricating qualitydesired.

Having thus described my invention,

What I claim as new, and desire to secure by Lettcrs Patent of the United States, is-- An alloy or composition of metals for metallic sabots for projectiles, composed of copper, tin, and lead, in all proportions.

THOMAS TAYLOR.

Witnesses A. BREASTED, THOMAS TAYLOR, Jr. 

